/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package com.l2jfrozen.gameserver;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ScheduledFuture;
import java.util.logging.Logger;

import javolution.util.FastList;

import com.l2jfrozen.Config;
import com.l2jfrozen.gameserver.ai.CtrlEvent;
import com.l2jfrozen.gameserver.managers.DayNightSpawnManager;
import com.l2jfrozen.gameserver.model.L2Character;
import com.l2jfrozen.gameserver.thread.ThreadPoolManager;

/**
 * This class ...
 * 
 * @version $Revision: 1.1.4.8 $ $Date: 2005/04/06 16:13:24 $
 */
public class GameTimeController
{
	static final Logger _log = Logger.getLogger(GameTimeController.class.getName());

	public static final int TICKS_PER_SECOND = 10;
	public static final int MILLIS_IN_TICK = 1000 / TICKS_PER_SECOND;

	private static GameTimeController _instance = new GameTimeController();

	protected static int _gameTicks;
	protected static long _gameStartTime;
	protected static boolean _isNight = false;

	private static List<L2Character> _movingObjects = new FastList<L2Character>();

	protected static TimerThread _timer;
	private ScheduledFuture<?> _timerWatcher;

	/**
	 * one ingame day is 240 real minutes
	 */
	public static GameTimeController getInstance()
	{
		return _instance;
	}

	private GameTimeController()
	{
		_gameStartTime = System.currentTimeMillis() - 3600000; // offset so that the server starts a day begin
		_gameTicks = 3600000 / MILLIS_IN_TICK; // offset so that the server starts a day begin

		_timer = new TimerThread();
		_timer.start();

		_timerWatcher = ThreadPoolManager.getInstance().scheduleGeneralAtFixedRate(new TimerWatcher(), 0, 1000);
		ThreadPoolManager.getInstance().scheduleGeneralAtFixedRate(new BroadcastSunState(), 0, 600000);

	}

	public boolean isNowNight()
	{
		return _isNight;
	}

	public int getGameTime()
	{
		return _gameTicks / (TICKS_PER_SECOND * 10);
	}

	public static int getGameTicks()
	{
		return _gameTicks;
	}

	/**
	 * Add a L2Character to movingObjects of GameTimeController.<BR>
	 * <BR>
	 * <B><U> Concept</U> :</B><BR>
	 * <BR>
	 * All L2Character in movement are identified in <B>movingObjects</B> of GameTimeController.<BR>
	 * <BR>
	 * 
	 * @param cha The L2Character to add to movingObjects of GameTimeController
	 */
	public synchronized void registerMovingObject(L2Character cha)
	{
		if(cha == null)
			return;

		if(!_movingObjects.contains(cha))
		{
			_movingObjects.add(cha);
		}
	}

	/**
	 * Move all L2Characters contained in movingObjects of GameTimeController.<BR>
	 * <BR>
	 * <B><U> Concept</U> :</B><BR>
	 * <BR>
	 * All L2Character in movement are identified in <B>movingObjects</B> of GameTimeController.<BR>
	 * <BR>
	 * <B><U> Actions</U> :</B><BR>
	 * <BR>
	 * <li>Update the position of each L2Character</li> <li>If movement is finished, the L2Character is removed from
	 * movingObjects</li> <li>Create a task to update the _knownObject and _knowPlayers of each L2Character that
	 * finished its movement and of their already known L2Object then notify AI with EVT_ARRIVED</li><BR>
	 * <BR>
	 */
	protected synchronized void moveObjects()
	{
		// Get all L2Character from the ArrayList movingObjects and put them into a table
		L2Character[] chars = _movingObjects.toArray(new L2Character[_movingObjects.size()]);

		// Create an ArrayList to contain all L2Character that are arrived to destination
		List<L2Character> ended = null;

		// Go throw the table containing L2Character in movement
		for(L2Character cha : chars)
		{

			// Update the position of the L2Character and return True if the movement is finished
			boolean end = cha.updatePosition(_gameTicks);

			// If movement is finished, the L2Character is removed from movingObjects and added to the ArrayList ended
			if(end)
			{
				_movingObjects.remove(cha);
				if(ended == null)
				{
					ended = new FastList<L2Character>();
				}

				ended.add(cha);
			}
		}

		// Create a task to update the _knownObject and _knowPlayers of each L2Character that finished its movement and of their already known L2Object
		// then notify AI with EVT_ARRIVED
		// TODO: maybe a general TP is needed for that kinda stuff (all knownlist updates should be done in a TP anyway).
		if(ended != null)
		{
			ThreadPoolManager.getInstance().executeTask(new MovingObjectArrived(ended));
		}

	}

	public void stopTimer()
	{
		_timerWatcher.cancel(true);
		_timer.interrupt();
	}

	class TimerThread extends Thread
	{
		protected Exception _error;

		public TimerThread()
		{
			super("GameTimeController");
			setDaemon(true);
			setPriority(MAX_PRIORITY);
			_error = null;
		}

		@Override
		public void run()
		{
			try
			{
				for(;;)
				{
					int _oldTicks = _gameTicks; // save old ticks value to avoid moving objects 2x in same tick
					long runtime = System.currentTimeMillis() - _gameStartTime; // from server boot to now

					_gameTicks = (int) (runtime / MILLIS_IN_TICK); // new ticks value (ticks now)

					if(_oldTicks != _gameTicks)
					{
						moveObjects(); // XXX: if this makes objects go slower, remove it
						// but I think it can't make that effect. is it better to call moveObjects() twice in same
						// tick to make-up for missed tick ?   or is it better to ignore missed tick ?
						// (will happen very rarely but it will happen ... on garbage collection definitely)
					}

					runtime = System.currentTimeMillis() - _gameStartTime - runtime;

					// calculate sleep time... time needed to next tick minus time it takes to call moveObjects()
					int sleepTime = 1 + MILLIS_IN_TICK - (int) runtime % MILLIS_IN_TICK;

					//_log.finest("TICK: "+_gameTicks);

					sleep(sleepTime); // hope other threads will have much more cpu time available now
					// SelectorThread most of all
				}
			}
			catch(Exception e)
			{
				if(Config.ENABLE_ALL_EXCEPTIONS)
					e.printStackTrace();
				
				_error = e;
			}
		}
	}

	class TimerWatcher implements Runnable
	{
		public void run()
		{
			if(!_timer.isAlive())
			{
				String time = new SimpleDateFormat("HH:mm:ss").format(new Date());
				_log.warning(time + " TimerThread stop with following error. restart it.");
				if(_timer._error != null)
				{
					_timer._error.printStackTrace();
				}

				_timer = new TimerThread();
				_timer.start();
			}
		}
	}

	/**
	 * Update the _knownObject and _knowPlayers of each L2Character that finished its movement and of their already
	 * known L2Object then notify AI with EVT_ARRIVED.<BR>
	 * <BR>
	 */
	class MovingObjectArrived implements Runnable
	{
		private final List<L2Character> _ended;

		MovingObjectArrived(List<L2Character> ended)
		{
			_ended = ended;
		}

		public void run()
		{
			for(L2Character cha : _ended)
			{
				try
				{
					cha.getKnownList().updateKnownObjects();
					cha.getAI().notifyEvent(CtrlEvent.EVT_ARRIVED);
				}
				catch(NullPointerException e)
				{
					if(Config.ENABLE_ALL_EXCEPTIONS)
						e.printStackTrace();
				}
			}
		}
	}

	/**
	 * @param rise
	 */
	class BroadcastSunState implements Runnable
	{
		public void run()
		{
			int h = getGameTime() / 60 % 24; // Time in hour
			boolean tempIsNight = h < 6;

			// If diff day/night state
			if(tempIsNight != _isNight)
			{
				// Set current day/night varible to value of temp varible
				_isNight = tempIsNight;
				DayNightSpawnManager.getInstance().notifyChangeMode();
			}
		}
	}
}
